This present invention is generally in the field of an electrically controlled hydraulic diaphragm valve and it is connected also with a flow command valve therefor. The invention is also concerned with other compounds of the diaphragm valve and its control.
Electrical valves of the aforementioned type are used in a variety of applications in which it is desired to control flow through a hydraulic supply line.
In diaphragm valves, the diaphragm itself is disposed between a fluid inlet of the valve""s housing and the valve""s outlet. There is provided a closure member having a surface area greater than that of the inlet passage. The valve is closed by forcing the closure member against the diaphragm so as to distort the diaphragm onto the fluid inlet, thereby sealing the valve. If the closure member is operated via an electric motor, then one way to apply sufficient force to the closure member would be to employ a correspondingly powerful motor. However, it is usually a requirement to minimize the motor, as much as possible, in order to overcome the valve size, as well as its cost. Miniature electric motors are usually incompatible with the requirement to provide high closure force. Therefore, a transmission mechanism must be employed in order to increase the effective motor force.
Apart from providing a transmission mechanism, it is also required to provide some control means for selectively controlling liquid flow through channels within the valve""s housing, said liquid used as a pressurizing media for displacing the diaphragm valve into sealing engagement over a suitable valve seating, whereby the valve is closed.
It is readily noted that some suitable electric circuitry is required and a variety of such switching circuits are available. However, it is one of the objects of the present invention to provide some improved such switching circuitry.
By a first aspect of the present invention there is provided a novel diaphragm valve. By a second aspect of the present invention there is provided a flow command module for controlling a diaphragm valve in accordance with the present invention.
In accordance with the first aspect of the present invention, there is provided a hydraulic diaphragm valve comprising a main valve housing; a valve inlet and a valve outlet; a diaphragm valve seating formed in said housing and located in a flow-path between said inlet and said outlet; a sealing diaphragm mounted in said housing and displaceable towards and away from said diaphragm valve seating so as to close and open said flow path; a valve control chamber defined between said sealing diaphragm and said housing, and outside said flow-path;
a command valve associated with said valve housing and comprising a first duct communicating at one end thereof with said valve inlet and, at an opposite end thereof, with a first command valve seating; a second duct communicating at one end thereof with said valve outlet and, at an opposite end thereof, with a second command valve seating; a third duct communicating at one end thereof with said valve control chamber and, at its opposite end, selectively with said first and second command valve seatings; a flexible command diaphragm juxtaposed with respect to said first and second command valve seatings; and selectively actuatable biasing means for selectively biasing said command diaphragm into seating engagement with one or other of said command valve seatings so as selectively to effect communication between said third duct and that command valve seating not in sealing engagement with said command diaphragm.
Preferably, said command valve furthermore comprises a command well structure said first and second command valve seatings being located therein, said command diaphragm being positioned in a mouth portion of said well structure so as to overlie said command value seatings.
Still preferably, said valve housing comprises first and second valve housing components with said sealing and command diaphragm held in position between them, said sealing diaphragm defining with said first valve housing component valve inlet and outer chamber respectively communicating with said valve inlet and outlet and, with said second valve component, said valve control chamber.
In accordance with a preferred embodiment, said valve inlet and outlet chambers are of substantially coaxial structure with said outlet-chamber being surrounded by said inlet chamber which is of substantially annular cross-sectional shape, said chambers being separated by a substantially cylindrical wall having an edge portion constituting said diaphragm valve seating.
In accordance with one specific design of the valve, said well structure is formed in said valve housing and wherein said command diaphragm is formed with an outlet aperture communicating with an interior of said well structure, and via said third duct with said valve control chamber.
By a specific embodiment, there is furthermore provided a valve override cock comprising a displaceable shutter located in said outlet-chamber displaceable into and out of interrupting communication between said outlet chamber and said valve outlet and manually actuatable means coupled to said shutter for displacement thereof.
In accordance with a different application, said command well structure is formed in a separate command valve housing there being provided means for mechanically and hydraulically coupling the command valve housing to said valve housing and wherein said third duct communicates on the one hand with an aperture formed in said well structure and, on the other hand, via a coupling port formed in said command valve module, with said valve control chamber. Where the command valve is in separate form, it can be applied onto a large variety of diaphragm valves and may be used as an add-on accessory.
In accordance with one embodiment of the present invention, said valve housing is formed with first and second coupling ports respectively coupled to said valve inlet and outlet and wherein said command valve housing is formed with first and second coupling ports respectively coupled on the one hand to said first and second command valve seatings and on the other hand to said valve housing first and second coupling ports and wherein said main valve housing comprises first and second valve housing components with said sealing and command diaphragm held in position between them, said sealing diaphragm defining with said first valve housing component valve inlet and outer chamber respectively communicating with said valve inlet and outlet and, with said second valve component, said valve control chamber, there being furthermore formed in such second valve housing component a communicating duct which communicates at one end with said valve control chamber and, at an opposite end with a coupling boss which is coupled with a third command housing port.
By a modification of this embodiment, said command housing is formed with first and second enclosures respectively coupled to said first and second command housing coupling ports and to said first and second command valve seatings.
In accordance with a further modification, said command valve seatings are respectively formed by outer rims of first and second nozzles disposed in said well structure and coupled to said first and second command valve coupling parts and wherein said command diaphragm is sealingly supported in said well structure so as to overlie said outer rims.
In accordance with still another embodiment, there is furthermore provided pressure control means for ensuring a substantially constant pressure outflow from said valve.
In accordance with one particular design, said pressure control means comprise flow rate reducing means associated with said second enclosure, an auxiliary flow pathway formed in said command valve housing coupled at one end to said second command housing coupling port and at an opposite end to said command housing third coupling port and including a flow path of said flow rate reducing means, and a constant flow pressure control means associated with said first enclosure and having an inlet coupled to said third command coupling port and an outlet coupled to said first command coupling port.
By one modification, said flow rate reducing means and said constant flow pressure control means are respectively incorporated in sealing plugs adapted to be removably fitted to said enclosures.
By another modification, said enclosures are respectively formed with central tubular portions which are respectively spaced apart from walls of said enclosures and which project outwardly from a central partition wall serving to separate said enclosures, there being formed within said command valve housing a communication duct between said second tubular portion and said third coupling port and constituting part of said auxiliary pathway.
In accordance with one specific embodiment, said sealing plugs are respectively formed with central projections, the projection of the pressure control means sealing plug being adapted to fit sealingly into said first tubular portion with the plug outlet being located within the first tubular portion, the projection of the flow rate reducing sealing plug being formed with a labyrinthine groove so as to define with said second tubular portion in which it is adapted to fit sealingly a labyrinthine groove having an inlet located within said second enclosure in communication with said second command communication port and being an outlet located within said second tubular portion.
By another specific embodiment, one of said sealing plugs is formed with a projection adapted to fit sealingly within said second tubular portion so as to seal off said auxiliary pathway.
In accordance with a second aspect of the present invention, there is provided a command valve module for use in controlling opening and closing of a flow valve and comprising a command valve housing, first and second enclosures of said housing separated by a central portion wall of the housing; first and second central tubular portions located respectively in such enclosures and respectively spaced from walls of said enclosures; a command valve well structure formed in said housing; first and second spaced apart nozzles formed in said well structure and respectively communicating, via ducts formed in said housing with first and second coupling ports of said housing; an aperture formed in said well structure and coupled via a duct formed in said housing with a third coupling port; outlet rims of said first and second nozzles constituting first and second command valve seatings; and a command valve diaphragm sealingly supported in said well structure so as to overlie said command valve seatings.
Preferably said first and second enclosures are respectively provided with removable first and second sealing plugs.
In accordance with an embodiment of this aspect of the invention, said first and second sealing plugs respectively serve as pressure controlling and flow rate reducing means and are respectively adapted to seal the first and second enclosures; said first and second plugs being respectively formed with first and second central projections, said first projection being adapted to fit sealingly into said first tubular portion an outlet of said first plug being located within said first tubular portion and an inlet of said first plug being located within said first enclosure, said second projection being formed with a labyrinthine groove so as to define with said second tubular portion in which it is adapted to be sealingly fitted, a labyrinthine groove having an inlet located within said second enclosure in communication with said second communication port and having an outlet located within said second tubular portion, there being formed within said command valve housing a communication duct between said second tubular portion and said third coupling port and forming part of an auxiliary pathway.
In accordance with a different embodiment, there are additionally provided a pair of alternative sealing plugs for use solely in sealing said enclosures and wherein one of said sealing plugs is formed with a projection adapted to fit sealingly within said second tubular portion so as to seal off said auxiliary pathway.